This invention relates to a latch bolt mechanism for a door, and particularly to a latch bolt mechanism in which the bolt may be drawn to open the door by use of energy stored in the mechanism as the door is being closed.
In conventional latch bolt mechanisms, the bolt is drawn by turning a key or a handle. Such mechanisms are not entirely suitable for certain special applications; for example where the user is unable through age or incapacity to operate the handle or key conveniently. When conventional latch bolt mechanisms are operated electronically, the energy required to draw the bolt necessitates not only greater power usage but additional machinery which cannot always be conveniently located on or in the door, and also adds substantially to the cost of the mechanism.